Give an error when setting break points in functions either defined through...

Give an error when setting break points in functions either defined through the API or in functions which are part of the V8 builtins.

BUG=178
Review URL: http://codereview.chromium.org/13785

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@977 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/debug-delay.js

@@ -474,10 +474,18 @@ Debug.findBreakPoint = function(break_point_number, remove) {
 
 Debug.setBreakPoint = function(func, opt_line, opt_column, opt_condition) {
   if (!IS_FUNCTION(func)) throw new Error('Parameters have wrong types.');
+  // Break points in API functions are not supported.
+  if (%FunctionIsAPIFunction(func)) {
+    throw new Error('Cannot set break point in native code.');
+  }
   var source_position = this.findFunctionSourcePosition(func, opt_line, opt_column) -
                         this.sourcePosition(func);
   // Find the script for the function.
   var script = %FunctionGetScript(func);
+  // Break in builtin JavaScript code is not supported.
+  if (script.type == Debug.ScriptType.Native) {
+    throw new Error('Cannot set break point in native code.');
+  }
   // If the script for the function has a name convert this to a script break
   // point.
   if (script && script.name) {

src/runtime.cc

@@ -919,6 +919,18 @@ static Object* Runtime_FunctionSetPrototype(Arguments args) {
 }
 
 
+static Object* Runtime_FunctionIsAPIFunction(Arguments args) {
+  NoHandleAllocation ha;
+  ASSERT(args.length() == 1);
+
+  CONVERT_CHECKED(JSFunction, f, args[0]);
+  // The function_data field of the shared function info is used exclusively by
+  // the API.
+  return !f->shared()->function_data()->IsUndefined() ? Heap::true_value()
+                                                      : Heap::false_value();
+}
+
+
 static Object* Runtime_SetCode(Arguments args) {
   HandleScope scope;
   ASSERT(args.length() == 2);

src/runtime.h

@@ -160,6 +160,7 @@ namespace v8 { namespace internal {
   F(FunctionGetSourceCode, 1) \
   F(FunctionGetScript, 1) \
   F(FunctionGetScriptSourcePosition, 1) \
+  F(FunctionIsAPIFunction, 1) \
   F(GetScript, 1) \
   \
   F(ClassOf, 1) \